Darrell Markewitz is a professional blacksmith who specializes in the Viking Age. He designed the living History program for L'Anse aux Meadows NHSC (Parks Canada) and worked on a number of major international exhibits. A recent passion is experimental iron smelting.
'Hammered Out Bits' focuses primarily on IRON and the VIKING AGE

Monday, October 31, 2011

Well, Alien (1979) if you like things that jump out of the dark at you.

But one of my favourite films of all time is John Carpenter's the Thing (1982)

The film is loosely based on the older 'The Thing from Another World' (1951), itself based on the classic James Campbell novella 'Who Goes There?'
The film has a wonderful atmosphere, crafted from camera, lighting and sound track. Absolutely great special effects, mainly because it was one of the last huge horror films to use actual life sized models rather than digital effects.

Why does it scare me?

Remember all those times you sat watching some film, and you saw someone flick a light switch, find the lights don't work, and said " Don't go IN there, you idiot!'!
And sure as shit, bozo walks into the dark, and straight into the monster.
Or you watched someone walking * backwards * down the hall, when they * know * there is a crazed maniac with a chainsaw loose in there someplace?
Or they are being chased by a hoard of blood sucking zombies, yet they run past a * shot gun * and instead pick up a golf club?

Ok, a bunch of American scientists in Antartica are kind of attacked by a couple of crazed Norwegians from the only nearby base. Wondering why, they go there, only to find everyone slaughtered, a huge wreck of a space craft uncovered in the ice, an empty coffin sized block of ice - and some very, very bizarre remains. Of * course * they have to haul that back to home base.
Later that night, frantic howling comes from the dog pens.
MacReady (played by Kurt Russell), on hearing the ruckus, hits the fire alarm, and his first command on the way over to the area is 'Get the flame thrower!'

What the Frack??
Who hears a bunch of dogs barking and sends for a flamethrower?
Did the character read the script before hand?
Would that be * your * first impulse?

(If so, you may be one of my close friends, but go with me here, ok?)

Now here's the part that scares me...

It doesn't do them all any damn good.
They all die anyway, mostly horribly.
Other than MacReady and one other, who might actually be alien shape changers themselves at that point anyway (and the end of the film certainly suggests this).

And the kids are scared of Frackin' ZOMBIES ...

I guess it beats worrying about glowing in the dark during a Nuclear Winter?

Holes were drilled through the furnace walls at roughly every 10 cm, starting at 10 cm above the interior base.
Measurements were taken using an industrial quality digital pyrometer (HH12B from Omega
equipped with standard bare metal type K thermocouples).
The probes were inserted roughly 5 cm beyond the interior surface of the furnace wall.
Measurements were taken roughly every hour over the course of the smelt event.

Because the probes did not reach into the central core of the furnace, there is every possibility that the central furnace temperatures were even higher than what was recorded.
Our thermocoples failed (melted!) at roughly 1350 C. On several recordings, this temperature was reached.

Image : Neil takes readings, early in the smelt

Time

Elapsed

base

tuyere

plus 10

plus 20

plus 30

plus 40

top

10 cm

20 cm

30 cm

40 cm

50 cm

60 cm

70 cm

12:06

:06

653

890

749

579

343

13:05

1:05

1042

1335

1300

1145

1002

610

13:50

1:50

328

1051

plus 1350

1195

1189

1014

660

15:12

3:12

995

1226

1268

1293

1128

1011

608

16:32

4:32

1124

1265 *

909

700

719

Note : It has been suggested by some theoretical researchers that temperatures above 1200 C are impossible to achieve inside a charcoal fired furnace...

Friday, October 21, 2011

Showing the initial layout of the 'pit'. A standard 20 L plastic pail was surrounded by dirt, then filled to top with cut willow branches (about 0.5 - 1 cm diameter). Use of concrete blocks would allow for easy excavation after the experiment.

Slag block as excavated (furnace itself was removed in one piece and retained for further use) There was no actual bloom recovered!

A fragment of the slag block, showing how hot slag had dripped down between the sticks, solidified, the heat converting the wood to charcoal. This from the front side of the furnace, indicating lack of iron (pale green colour). Slag to the rear of the furnace was a black iron rich colour.

The purity of the ore was questionable.There is a chance some iron may exist trapped inside the slag block. A check with a magnet at the usual location (under the tuyere) did not indicate any however.It is possible that the existing iron rich slag might be recovered, then utilized in a second smelt attempt.

For now we want to retain the slag block itself as a sample.

The extracted slag block. In this shot the tuyere is located to the upper right, directly above the scale vertical line. The colour shift in the slag from the rear to the front of the furnace is easily seen. There is an extra bulge in the slag about at ground level (the clay furnace sat directly on the loose dirt here.

Saturday, October 01, 2011

One of the traditional iron smelt events at Wareham is over Thanksgiving
weekend. This is 'Darrell's Smelt' (originally a sad replacement for
Early Iron after that event was dropped). The DARC team normally takes
part.

Because Thanksgiving is a family day for many, and because some people
get involved with the archery stuff in KW also that weekend, Smelt Day
is SUNDAY.

Vandy and I will be prepared to welcome guests any time after 9 AM.
The primary working day is SUNDAY, for those intending on a one day trip.
As usual, this is a 'limited open' event - please drop me a post back if
you are intending on coming up.

Going into 2012, I want to work towards a new furnace type. I have
proposed to Goderich Celtic Festival that I undertake a smelting demo at
their event next August. This would be a Celtic Iron Age, slag pit type
furnace. The style applies to early Danish and Anglo Saxon as well.
The upper portion of the planned furnace is going to be much like our
standard types (short shaft, clay cobb construction). I have a wide
number of ore types on hand, and have not determined which I may use.
(Likely one of the Virginia rock ores, as I have considerable of those
materials.)

Any working advice from our friends in England and Denmark, who have
worked with these type of furnaces, would be helpful!

Subscribe

Ontario Arts Council

Canada Council

Ontario Arts Council

February - May 2012 : 'Bloom to Bar' Project Grant

February 15 - May 15, 2012 : Supported by a Crafts Projects - Creation and Development Grant

COPYRIGHT NOTICE -
All posted text and images @ Darrell Markewitz. No duplication, in whole
or in part, is permitted without the author's expressed written permission.
For a detailed copyright statement : go HERE